Low-temperature relaxation process and memory effect in a nonstoichiometric magnetite of Fe 3−δ O 4 with δ =0.03

2014 ◽  
Vol 360 ◽  
pp. 178-182 ◽  
Author(s):  
J.Y. Xiang ◽  
Y.F. Lv ◽  
F.S. Wen ◽  
W.T. Hu ◽  
W.M. Lv ◽  
...  
Keyword(s):  
Low Temperature ◽  
Relaxation Process ◽  
Memory Effect ◽  
Temperature Relaxation

Effect of Defects on Dielectric Properties in KTiOPO4, KTiOAsO4, RbTiOAsO4 and CsTiOAsO4 Single Crystals

1996 ◽  
Vol 453 ◽  
Author(s):  
A. R. Guo ◽  
Z. -Y. Cheng ◽  
R. S. Katiyar ◽  
Ruyan Guo ◽  
A. S. Bhalla
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Dielectric Relaxation ◽  
Relaxation Process ◽  
Single Crystals ◽  
Cage Structure ◽  
Dielectric Relaxation Process ◽  
Alkali Ions ◽  
Temperature Range ◽  
Temperature Relaxation

AbstractDielectric measurements were carried out in single crystals of KTiOPO4, KTiOAsO4, RbTiOAsO4 and CsTiOAsO4. All of the materials exhibit a clear dielectric relaxation process in the low temperature range and a conductance mechanism in the high temperature range. The dielectric relaxation process can be well described by the Debye dielectric model with an activation energies of 0.8 eV, 0.5 eV and 0.4 eV respectively. The relaxation process is associated with the deviation of the alkali ions from its ideal lattice positions. The high temperature conductance is associated with the motion of the alkali ions from one lattice site to another. Therefore, both the low temperature relaxation process and the high temperature conductance originate from different features of defect behavior of alkali ions in the cage structure of these materials.

Low-Temperature Relaxation and Elastic Properties of YBa2Cu3Ox with Different Oxygen Content

1993 ◽  
Vol 119-121 ◽  
pp. 701-706 ◽  
Author(s):  
H.-J. Kaufmann ◽  
P.P. Pal-Val ◽  
L.N. Pal-Val ◽  
V.D. Natsik ◽  
J. Fickert ◽  
...  
Keyword(s):  
Low Temperature ◽  
Elastic Properties ◽  
Oxygen Content ◽  
Temperature Relaxation

scholarly journals Reduction of titanium oxide in the presence of nickel by nonequilibrium hydrogen gas

2009 ◽  
Vol 24 (7) ◽  
pp. 2391-2399 ◽  
Author(s):  
Hidehiro Sekimoto ◽  
Tetsuya Uda ◽  
Yoshitaro Nose ◽  
Shigeo Sato ◽  
Hiroaki Kakiuchi ◽  
...  
Keyword(s):  
Low Temperature ◽  
Relaxation Process ◽  
Reduction Potential ◽  
Hydrogen Plasma ◽  
Equilibrium Phase ◽  
Hydrogen Gas ◽  
X Ray Diffraction ◽  
Energy Process ◽  
X Ray ◽  
The Difference

We investigated the reduction of TiO2 in the presence of Ni by nonequilibrium hydrogen gas, including low-temperature hydrogen plasma at 800 °C and supercooled monatomic hydrogen at 1000 °C. TiO2 was reduced to Ti2O3, which is not in equilibrium phase, by low-temperature hydrogen plasma. The results of x-ray diffraction and energy dispersive x-ray analysis in experiments at 1000 °C indicate that the thermodynamical reduction potential of supercooled monatomic hydrogen is almost the same as atmospheric hydrogen gas. However, the wide Ti3O5 layer formed only in the case of the reduction at 1000 °C by supercooled monatomic hydrogen. With these experimental facts, we speculate that the reduction mechanism by nonequilibrium hydrogen consists of two steps; the releasing energy process and the relaxation process. We can explain the difference of reduction products by nonequilibrium hydrogen gas on the assumption of the rate of the relaxation process between 800 and 1000 °C.

Anelastic Effects on Martensitic Carbon Steels during First Stage of Tempering

2012 ◽  
Vol 184 ◽  
pp. 221-226 ◽  
Author(s):  
J.J. Hoyos ◽  
A.A. Ghilarducchi ◽  
H.R. Salva ◽  
J.M. Vélez
Keyword(s):  
Carbon Steel ◽  
Low Temperature ◽  
Internal Friction ◽  
Relaxation Process ◽  
Forced Vibration ◽  
Carbide Precipitation ◽  
Carbon Steels ◽  
Deformation Amplitude ◽  
Temperature Rate ◽  
Internal Friction Spectrum

The evolution of martensitic carbon steel during low temperature tempering was studied using internal friction. The steel containing 0.71wt.% carbon was heated at 1093K for 5min and then rapidly cooled into water (quenched), and tempered for 10 min at 340, 380, 420 and 460K. Additionally, other samples were tempered at 380K for 1 and 20 hours. Internal friction was measured by using a forced vibration pendulum, in a temperature range from 300 to 600K, with deformation amplitude 3 x 10-6 and temperature rate of 0.8 K/min. The internal friction spectrum is decomposed into three Debye peaks: P1 at 380K, P2 at 420K and P3 at 480K, for 3 Hz. P1 is attributed to the epsilon carbide precipitation. P2 and P3 are associated to the dislocation relaxation process. P2 appears when dislocations are pinning with epsilon carbide and P3 appears when dislocations are pinning with cementite carbide.

Memory Effect of Low-Temperature Processed ZnO Thin-Film Transistors Having Metallic Nanoparticles as Charge Trapping Elements

2012 ◽  
Vol 12 (2) ◽  
pp. 1344-1347
Author(s):  
Young-Su Park ◽  
Soo-Jin Kim ◽  
Si-Hoon Lyu ◽  
Byoung Hoon Lee ◽  
Myung Mo Sung ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Memory Effect ◽  
Thin Film Transistors ◽  
Metallic Nanoparticles ◽  
Charge Trapping ◽  
Zno Thin Film

Long-Time, Low-Temperature Relaxation in Spin Glasses

1986 ◽  
Vol 2 (10) ◽  
pp. 797-803 ◽  
Author(s):  
J. L. van Hemmen ◽  
G. J Nieuwenhuys
Keyword(s):  
Low Temperature ◽  
Spin Glasses ◽  
Long Time ◽  
Temperature Relaxation

Grain growth behavior of a nanostructured 5083 Al–Mg alloy

2001 ◽  
Vol 16 (4) ◽  
pp. 938-944 ◽  
Author(s):  
V. L. Tellkamp ◽  
S. Dallek ◽  
D. Cheng ◽  
E. J. Lavernia
Keyword(s):  
Activation Energy ◽  
Stress Relaxation ◽  
Low Temperature ◽  
Grain Boundaries ◽  
Relaxation Process ◽  
Grain Growth ◽  
Alloy Powder ◽  
Growth Behavior ◽  
Mg Alloy ◽  
Grain Growth Behavior

A nanostructured 5083 Al–Mg alloy powder was subjected to various thermal heat treatments in an attempt to understand the fundamental mechanisms of recovery, recrystallization and grain growth as they apply to nanostructured materials. A low-temperature stress relaxation process associated with reordering of the grain boundaries was found to occur at 158 °C. A bimodal restructuring of the grains occurred at 307 °C for the unconstrained grains and 381 °C for the constrained grains. An approximate activation energy of 5.6 kJ/mol was found for the metastable nanostructured grains, while an approximate activation energy of 142 kJ/mol was found above the restructuring temperature.

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